Box erecting machine



April 17, 1962 Filed June 9, 1959 M. B. DUNN BOX ERECTING MACHINE 3Sheets-Sheet 1 L:is 2||4 INVENTOR MAURICE B. DUNN ATTORNEYS April 17,1962 M. B. DUNN Box ERECTING MACHINE 3 Sheets-Sheet 2 Filed June- 9,1959 INVENTOR MAURICE B. DUNN ATTORNEYS April 17, 1962 M. B. DUNN3,029,712

BOX ERECTING MACHINE Filed June 9, 1959 3 Sheecs-Sheet 3 INVENTORMAURICE B. DUNN ATTORNEYS States This invention relates `to a machinefor setting up or erecting paper board cartons into condition foruse inthe packaging of commodities and more particularly to improvements iusuch machine for setting up into box or tray form a cut and scored iiatbox blank of the cornerlock type.

It is an object of the present invention to provide a plunger and dieassembly operable during movement of the plunger through the die cavityto open the cuts in a box blank of the type described and to insert andinterlock the tabs within the cuts at each corner of the blank in asimple and efficient manner.

Another object of the present invention is the provisionV of a plungerand die assembly of the type described having improved means for eectinginterlock between each tab and cut of a box blank of the type described.

A further object of the present invention is the provision of a plungerand die assembly of the type described having improved means for guidingsuccessive box blanks horizontally over the die into an operativeposition between the plunger and die wherein the bottom panel of the boxblank is in transverse and horizontal registry with the die cavity.

A still further object of the present invention is the provision of aplunger and die assembly of the type described having improved means forpreventing buckling of the blank as a result of the leading edge thereofengaging the die during its movement into operative position thereon.

Still another object of the present invention is the provision of aplunger and die assembly of the type described which is simple inconstruction and economical to manu: facture and maintain.

These and other objects of the present invention will become moreapparent during the course of the following detailed description andappended claims.

The invention may best be understood with reference to the accompanyingdrawing wherein an illustrative embodiment is shown.

In the drawings:

FIGURE l is a fragmentary, horizontal, sectional view illustrating thebox erecting machine plunger and die assembly embodying the principlesof the present invention;

FIGURE 2 is a side elevational view of the assembly shown in FIGURE l;

FIGURE 3 is an end view of the plunger;

FIGURE 4 is a longitudinal, vertical, sectional viewV of the die; and

FIGURES 5, 6 and 7` are fragmentary, perspective views, partially brokenaway forV purposes of clearer illustration, showing progressive stepsduring the operation of the plunger and die assembly in eiecting theinter lock of the tab and cut at the corner of a box blank.

Box erecting machines capable of setting up into box form a cut andscored flat box blank are well known in the art. In general, suchmachines include a means for receiving a stack of iiat box blanks, meansfor feeding successive individual flat box blanks between a plunger anddie assembly which cooperate in response to relative verticalreciprocating movement to eifect erection of the blank into box form,and means for receiving the erected boxes and conveying them from themachine.

g IC@ As best shown in FlGURES l and 5 7, the present plunger and dieassembly is particularly adapted to set upat box blanks of the typewhich includes a main bottom panel 10 having hingedly connected alongscore line at opposite sides thereof a pair of opposed side walls 12,each of which is formed with an angular cut 14 adjacent opposite endsthereof. Each cut 14 denes an adjacent outer end portion 16 on theassociated side wall 12 and an adjacent inner end portion 18, the endportions 16 and 18 being dellectable relative to each other to open thecut 1li.V

The boxrblank also includes a pair of opposed end walls 24) hingedlyconnected along suitable score lines to opposite ends of the main bottompanel 10. As shown in dotted lines in FIGURE 1, the bottom panel ispreferably rectangular so that the end walls 20 extend in a directionsubstantially perpendicular to the side walls 12. Each end wall 20 hashingedly connected to each end thereof along a suitable score line anend flap 22. Each liap has its outer extremity cut to form a tab Z4arranged to enter an associated cut 14, when opened, and to interlockwith the associated outer end portion 16 to maiutain the associatedcorner of the box blank in erected condition, that is, with theassociated end-and side walls in upstanding position with respect to thebottom panel;

dimensionally. That is, a side wall is a wall which is associated withthe cuts in the blank rather than one 4which f is of a greater dimensionthan an end wall. Indeed, the

term side wall as used herein comprehends a Wall hav ing a dimensionless than the walls perpendicular thereto. Stated dierently, the endwalls are not necessarily the two shortest walls of the boxv blank,plunger or,die, and conversely the side walls are not necessarily thetwo-v longest walls of the four provided. The terms en p. and side havebeen used merely as a matter of c onvenience and if any significance isattached thereto it relates to the fact that the side walls are the onesasso-` ciated with cuts, whereas the end walls are the ones associatedwith the locking tabs.

The plunger and die assembly of the present invention is arranged toreceive successive blanks therebetween and to set up such blanks intobox form by relative verti- `cal reciprocating movement between theplunger and die.

In normal operation, the assembly is embodied in a machine provided withmeans for feeding successive blanks thereto. To this end, there is shownin FIGURE 1 a portion of the arrangement for guiding successive blankshorizontally into operative position between the plunger and dieassembly. As shown, this guiding arrangement includes a pair oftransversely spaced guide members 26 preferably in the form of angleirons.V

Preferably, each angle iron is disposed so that one of its flanges islhorizontal and the other flange is vertical and extends upwardly fromthe iirst. In addition, the angle irons are positioned so as to convergeslightly toward the plunger and die assembly so as to have a guidingeffect on the yblanks as they are moved therealong by means not shown.The horizontal surface of the blanks are preferably supported by a pairof transversely spaced Patented Apr. 17, 1962 The terms end wall andside wall as used herein` in describing certain portions of thestructure of the box; blank and of the plunger and die assembly are notlimitedV f i 3 supporting plates 28, each secured to the horizontalflang of an associated guide member 26. The die of the present plungerand die assembly comprises va pair of elongated side wall members 30 and32 preferably in the form of plates of vertically elongated rectangularcross-sectional configuration. The side wall members are mounted inspaced parallel relation by any Vsuitable means, such as lower crossbraces 34 extending between opposite ends of the side wall membersadjacent the lower surfaces thereof and upper cross braces 36 extendingbetween the side wall members at positions spaced inwardly from'thelower cross braces 34. The central portion of the side wall member 36defines a side wall engaging and folding means of the die. Secured tothecentral portion of the other side wall member '32 to dene another sidewall engaging and folding means of the die is a central plate 38 and twoend plates 40. The plates 38 and 40 are secured to 'the side wall 32 byany suitable means in positions so that each` end plate 40 is spacedfrom the 'associated lend of the central plate 38 to deiine'a channel orspace 42 in one side face of the die. Y

It will be noted that the uper surfaces of the blank supporting platesV28 are disposed above the upper surface of the side wall member 30, asshown in FGURE 2. ln order to guide the blank into proper position overthe die beneath the plunger, each upper cross brace 36 has mounted'thereon a guide member 44 in the form of ail angle iron having oneflange disposed horizontally in engagement with the upper surface of theassociated cross brace 32 and 'secured therewith by any suitable means,such as bolts 46 extending through transversely yelongated slots 48forlr'ned the horizontal flange of the guide membier. Each guide member:44 also includes a vertical flange extending upwardly from thehorizontal flange and arranged to engage "an edge of the at blank as itis moved horizontally into operative` position over the die.

Mounted 'on the outer end of the vertical ange of each v guide member'44.-l in "a position adjacent the side wall member 132(r is Ava stopblock 50 which is arranged to eng'a'ge the 'end -iiap of theblank'outwardly of the 'associated tab 24. lThe guide members '44 thusserve lto position each blank in proper relation to the die in onedirection while the stop blocks 50 serve to properly `position the blank-in `the other direction. A supporting plate 52 is Secured to lthe uppersurface of each cross brace 36 inwardly 'adjacent the associatedvertical iian'ge of the guide member 424 to support thefassociated endwall of the b'ln'k -as itis moved horizontally into operative position.

:In order to preyent the possibility of the blank buckling as 'a lresult'of the leading 'edge of the leading Yside wall l12 of the blankengaging the plates 38 vand 40 of th'e'die during the movement of 'theblank into operative position, there is provided a pair'of pivotedngerassemblies, vgenerally indicatedfat 54. Each pivoted finger assemblyincludes a block 56 secure'dtto the 'outer surface of the side wall 32,as by bolts 58. The upper surface of eachV block 56 is provided with varectangular recess 6i) which is valigned with'the space 42 Ibetween thecentral plate /38 and associated end plate 40. In addition, an alignedrecess 62 is formed in the upper surface of the side wall member 32.

Pivotally mounted 'within the recess 60, as by pivot pin64,i`is ablock66 having a finger or guide member 68 mounted in its upper surface. Eachnger v68 is provided with 'an upper surface having arearward portion 70which is normally disposed in a horizontal position l'and a forwfard`portion 72 disposed at van angle of lappr'Cutimately SC with respecttothe rearward portion. The weight of each block 66and nger 68 isdistributed relative to the associated pivot pin 64 so as to bias ormaintain thesnrface portion 70in its horizontal position and the surfaceportion 72 inv a position extending downwardly in front ofthecasciated-plate'ses and 4o. lrfthe^1eaaing edge 4 of the leading side wall 12 ofthe blank during its horizontal movement into operative position overthe die should curl under, it will be engaged by the inclined surfaceportions 72 and forced upwardly thereby over the upper surface of theplates 68 and 40 until the leading side wall 12 rests on the surfaceportions 70.

The inner surface of the side wall member 30 and the inner surfaces ofthe lplates 38 and 40 define the sides of a cavity 74 of the die, theends of which are formed by a pair of end wall members 76. As best shownin -FIGURE 4, each end wall member 76 has one end thereof extendingwithin a vertically elongated recess 78 formed in the side wall member3i) and connected therewith by a pivot pin 80 extending through the sideWall member 30 and the upper portion ofthe end wall member 76. The endplate 40 associated with each end Wall member 76 has its lower outercorner cut out, as indicated at 82, to receive the opposite 'end of theassociated end wall member 76 and ythe latter is connected with the`side wall member 32, as by a pivot pin 84 extending'thereth'rough andinto the upper portion of the associated end wall member in alignmentwith the associated pivot pin 80. l

It will be Vnoted that the inner edges of the recess 78 and cut out 82'engage the lower forward edge of the associated end wall member 75 vsoas to limit the inward pivotal movement thereof. Each end wall member 76is resiliently biased for inward movement by any suitable means, suc-has a pair of spaced coil springs 88 suitably connected between the lowerend of the associated e'n'd wall member 76 and the associated lowercross brace 34.`

Carried by the side wall meinberlin) -a'dj'acent each corner ofthecavity 74 is lan lou-ter end portion blank engaging assembly 90 and asimilar assembly 92 is carried oy the 'opposite side wall member 32 -ateach associated corner of the cavity 74. Each lassembly 90 includes aspring-pressed 'member inthe form of "a ball 94 mounted within avertically extending `aperture 96 'extending through the side wallmember 30. A b'ar`98 is secured to the outer surface of the side wallmember 30 adjacent the aperture 96 and lhas an aligned aperture 100formed therein. A 'coil spring X02 is mounted 'within the aperture 100and :has one 'end thereof disposed in engagement with a plate 104secured to the bar '98 iand its otherle'nd dsposed 'in engagement withthe ball to resiliently urge the latter 'toward the cavity. The innerend of' they aperture 96 is reduced in cross-section to prevent themovement of the b a'll 'beyond 'a limiting position wherein the4Aperiphery extends into'the die'c'avity 74.

Each assembly 92 includes a ball 106'r'nount'ed within an aperture108,similar to aperture 96, extending through the Vassoci-ated end ofjplate 230.- The side wall 32 has an aligned aperture 118 'formedtherein for receiving a coil spring 112 having 'oneend engaging the ball186 and its other end engaging a plate 114 suitably secured to the`outer surface of the side wall member 432, as by bolts 116. The ball m6Ais resiliently biased by the K spring 112 into 'fa limiting position ina manner similar tofthe ball 94.

The plunger of the present plunger and die assemly vcomprises 'a body,fgenerally indicated at 118, ywhich is preferably in 4rthe form of-acasting. vThe body M8 includes "a central, horizontally disclosedportion 12() havingr'end Vwalls 122 extending downwardly and outwardlytherefroinjat an inclination of approximately 5. Parallel 'side lwalls124 land :126 extend downwardly from opposite sides thereof, the "sidevwall `126 'having a portion extending'upwardly above thecentralhorizontal portion 1120. i Formed in yeach side wall 124 and 126is a pair of vertically extendingslots or recesses 128, each slot beingspaced from the associated end wall a distance slightly greater than thecorresponding distance ofthe cut i4 from 1the associated end ofthe sideflap. Thepurpbseof each recessis to permit ready'entry of reoiprocationbetween the plunger and die.

the associated tab during the interlocking of the tab and cut.

The portion of each Vside wall extending from each recess 128 to theassociated end of the body is relieved as indicated at 130. As shown inFIGURES l and -7, the relief 130 is preferably along a plane whichextends in a horizontal direction inwardly yfrom the adjacent plungerend at an angle of approximately 71/2 and which extends verticallyinwardly and upwardly an angle of approximately 71/2, Prefer-ably, aslight vertical marginal edge is provided, as indicated at 132.(Associated with each slot 12S is a plate 134 rigidly secured, as bybolts 136, to each side wall adjacent to and inwardly of each slot. Theupper outer end of each plate 134 has an inclined blank receiving knifeedge 138 formed thereon and disposed at an angle of approximately 45with respect -to the horizontal. Each plate also includes a verticalouter edge 140 spaced inwardly from the adjacent outer slot wall todefine a space for receiving the associated blank tab.

The end walls 122 and side walls 124 and 126 of the kdie body 11S havetheir lower surfaces disposed in a common horizontal plane, as indicatedat 142, for the purpose of engaging the bottom panel of the blank. Itwill be understood that the peripheral dimensions of the surface 142 areslightly less than the corresponding dimansions of the die cavity 74.

Operation As noted above, the plunger and die assembly described aboveis arranged to be embodied in a machine having means for feedingsuccessive dat box blanks thereto and means for receiving the set-up boxblanks and conveying the same away from the machine. Preferably, thefeeding means is arranged so as to move successive blanks horizontallyinto an operative position over the die cavity 74. To this end, theplates 28 serve to suppont the blanks for horizontal movement into suchposition while the vertical flanges of 4the guide members 26 serve toinsure that the blank will move into proper operative position betweenthe ilanges of the die guide members 44. As noted above, the lingerassemblies 54 are mounted so that they normally assume a positionwherein the surface portions 70 are disposed horizontally and thesurface portions 72 extend downwardly in front of the plates 38 and 40Kat an angle of approximately 30. Thus, as the blank is movedhorizontally over the die cavity the leading edge of the leading sidepanel 12 may engage the inclined surface portions 72 and be forcedupwardly onto the horizontal surfaces 70. This action insures that theleading edge will not engage the plates 3S and 40 so that the blank willbuckle during its movement into operative position. The horizontalmovement of the blank is limited by engagement of stop blocks 50therewith. In operative position, the blank is disposed as clearlyindicated in dotted lines in FIGURE 1, with the main bottom panel of theblank in transverse and longitudin-al registry with the die cavity 74,and the end walls of the blank resting on the plates 52.

It will be understood that when the present plunger and die assembly isembodied in an operative machine, means will be provided for effecting arelative vertical Preferably, the side wall members and 32 are rigidlysecured to the frame of the machine while the plunger is suitablycarried by a cross head mounted for ver-tical reciprocation on the frameof the machine. In this way, the plunger is mounted for verticalreciprocation through the cavltyrof the die.

Referring now more particularly to FIGURE 2, it will be noted that theplunger is disposed in a raised position above the die as the blank ismoved into operative position over the die. The blank is set up duringthe subsequent vertical movement of Ithe plunger through the die cavity.It will be noted that during the initial engage- 6 ment of the surface142 of the plunger body with the bottom panel of the blank, the lingerassemblies 54 will be pivoted in a counter-clockwise direction as viewedin FIGURE 5. At the same time the side walls 12 and end flaps 22 of theblank begin their upward folding movement.

Subsequently, the end walls 20 engage the upper end of the end wallmembers 76 of the die and begin their upward folding movement. As theplunger progresses downwardly into the die cavity 74, the spring pressedballs 94 and 106 will engage the outer end portions of the side walls 12of the blank, the latter being moved progressively downwardly past theballs so that the outer end portions are deflected inwardly against therelieved portions of the plunger.V The inner end portions of the sidewalls of the blank are maintained in the plane of the side walls 124 and126 of the plunger by engagement of the cut opening plates 134therewith, as is clearly illustrated in FIGURE 5. This operation has theeffect of opening the cuts 14 by relative deflection of the inner endportions 1S withv respect to the outer cud portions 16 adjacent the cut.

Further downward movement of the plunger results in the further foldingof the end walls into their upright positions which alsoreffects acomparable movement of the associated end flaps past the associatedspring pressed balls so that the tabs 24 will move within the openedcut, as shown in FIGURE 6, It will be noted that the outer edge' of eachtab is guided past the associated plate edge by the associated inclinedknife edge 138 and is allowed to enter the recess 12S during itsmovement through the cut. Of course, the end wall members 76 pivot intovertical alignment against the action of the springs 88 as the diepasses therethrough. As the folding movement of the end walls 219 of theblank into an upright position is completed the tabs 24 will have movedcompletely through the cuts and into slots 128 and thus becomeinterlocked with the side wall end portions. Atlthe same time the springpressed balls will have passed above the upper edges of the aps and sidewall end portions as is clearly illustrated in FIGURE 7.

The downward movement of the plunger continues until the upper edge ofthe set-up box passes beneath the lower edge of the die cavity definingmembers. In this regard, it will be noted that the inherent resiliencyof the paper board material of the blank will cause the end and sidewalls to bow out as they pass under the die cavity defining structure.Thus, when the plunger begins its upward travel the upper edges of theset-up box will engage the lower surface of the cavity defining membersand be stripped from the plunger, the spring urged pivotal mounting ofthe end wall member aiding in this action. As previously noted thestripped, set-up box blank is arranged to be received by means embodiedin the machine for conveying the same away.

It thus will be seen that the objects of this invention have been fullyand effectively accomplished.` It will be realized, however, that theforegoing specific embodiment has been shown and described only for thepurpose of illustrating the principles of this invention and is subjectto extensive change without departure from such principles. Therefore,this invention includes all modifcations encompassed within the spiritand scope of the following claims.

I claim:

1. In a machine for at least partially setting up into box form a cutand scored iiat box blank having a bottom panel, a pair of opposed sidewalls hinged to said bottom panel, each having a tab receiving cutformed therein at positions spaced inwardly from each end thereof todefine inner and outer end portions deectable with respect to each othertoV open said cut, and a pair of end walls hinged to said bottom paneleach having an end flap hinged to opposite ends thereof, each flaphaving a locking tab insertable into an associated tab receiving Y 7 cutto lock said walls in upstanding relation with respect to said bottompanel, the combination ccmprislng a dre having box blank wall engagingmeans defining a cav1ty of a size generally conforming to the size ofsaid bottom` panel, anda cooperating plunger movable relative to saiddie through the cavity thereof to set up a box blank moved horizontallyinto an operative position therebetween, means for guiding successiveflat box blanks intoY said operative position to insure that the bottompanel thereof is in transverse and longitudinal registry with said diecavity, said guiding means including a n nger having a guiding surfaceportion extending inwardly into said cavity below the adjacent uppersurface of said die and a supporting surface portion disposed outwardlyof said cavity above theadjacent upper surface of said die, said guidingsurface portion being positioned to engage the leading edge of a boxblank during its movement horizontally over said die toward saidoperative position and to guide such edge over the adjacent uppersur-face of said` die on to said supporting surface portion, said nngerbeing pivotally mounted on said die for movement of said guiding surfaceportion out of said cavity in response to the movement of said plungertherethrough, said plunger and die having cooperating means forinterlocking each locking tab and cut'during the movement of saidplunger through said die.

2. The combination as defined in claim l wherein said guiding meansincludes spaced guiding members carried by said die for engaging theedges of the blank parallel to the direction of movement of the blanktoward said operative position.

3. The combination as defined in claim l wherein said finger surfaceportions are planar and disposed at an angle of approximately thirtydegrees with respect to each other.

4. The combination as defined in claim l wherein said finger is biasedto move into a position wherein said guiding surface portion extendsinto said cavity.

5. The combination as denned in claim 4 wherein the weight of saidfinger is distributed on opposite sides of its pivot to bias the sameinto said position.

'6. The combination as defined in claim l wherein the box blank wallengaging means of said die provides recess means in one side of saidcavity for receiving the guiding surface portion of said finger whenmoved out Vof said cavity. t

7. In a machine for at least partially setting up into box form a cutand scored flat box blank having a bottom panel, a pair of opposed sidewalls hinged to said :bottom panel, each having a tab receiving cutformed therein at positions spaced inwardly from each end thereof todefine inner and outer end portions detlectable with respect to eachother to open said cut, and a pairfofend walls hinged to said bottompanel each having an end flap hinged to opposite ends thereof, each flaphaving a locking tab insertable into an associated tab receiving cut tolock said walls in upstanding relation with respect to said bottompanel, the combination comprising ya die having box blank wall engagingmeans defining a cavity of a size generally conforming to the size ofsaid `bottom panel, and a cooperating plunger movable relative to saidAdie through the cavity thereof to at least partially set up a box blankpositioned therebetween, said plunger having side walls disposed inparallel vertical planes, each side wall having a vertically extendingrecess formed therein in communicating relation 'to the bottom surfaceof said plunger and in spaced relation from at least one end of saidplunger a horizontal distance sufficient to permit entry of theassociated box blank tab therein during the setting up of the ylatter,the surface of each plunger side wall Aextending from said `one endthereof to the associated recess being defined -by a first line formingthe associated plunger corner and a'spaced second line forming theadjacent side of the associated recess, said first line lying in thevertical plane of theassociate side wall, the second lineat its lowerend being disposed 1n said associated vertical plane and extendinginwardly and upwardly, each plunger recess having a box blank inner endportion engaging plate extending from the opposite s ide thereof overthe same and terminating in spaced relation to the second line formingside of said recess, and means carried by Vsaid die cooperating witheach of said plunger surfaces for interlocking the associated lockingtab and cutv during the relative movement between said plunger and die.l

8. In a machine for at least partially setting up into box form a cntand scored at box blank having a bottom panel, a pair of opposed sidewalls hinged to said bottom panel, each having at least one tabreceiving cut formed therein at a position spaced inwardly from the endthereof to define inner and outer end portions defiectable with respectto each other to open said cut, and a pair of end walls hinged to saidbottom panel, each having at least one end flap hinged to the endthereof adjacent said one side wall, each flap having a locking tabinsertable into an associated tab receiving cut to lock said walls inupstanding relation with respect to said bottom panel, the combinationcomprising a die having box blank wall engaging means defining a cavityof a size generally conforming to the size of said bottom panel, and

a cooperating plunger movable relative to said die through the cavitythereof to at least partially set up a box blank positionedtherebetween, said plunger having side walls at least one of which isdisposed in a vertical plane, said one side wall having a pair ofvertically extending recesses formed therein in communicating relationto the bottom surface of said plunger in spaced relation from the endsof said plunger a horizontal distance sufficient to permit entry of theassociated box blank tab therein during the setting up of the latter,the suface of said one plunger side wall extending from each end thereofto the associated recess being defined by a first line forming theassociated plunger corner, and a spaced second kline forming theadjacent side of the associated recess, each first line lying in thevertical plane of said one side wall, each second line at its lower endbeing disposed in the vertical plane of said one side wall and extendinginwardly and upwardly, each plunger recess having a box blank inner endportion engaging plate extending from the opposite side thereof over thesame and terminating in spaced rela- Y tion to the second line formingside of the associated recess, and means carried by said die cooperatingwith each Vof said plunger surfaces for interlocking theassociatedlocking tab and cut during the relative movement between said plungerand die.

9. The combination as defined in claim 8 wherein said plate includes anouter surface disposed in the vertical plane of the associated side walland an inclined knife edge formed on the outer upper portion thereof.

10. The combination as defined in `claim 8 wherein said 'die wallengaging means includes side wall .members disposed in vertical planesand spaced end wall ymembers extending between said side wall members,and Vwherein said die interlocking means includes a horizontallyextended ball receiving opening vformed in each of said side wallmembers in closely spaced relation lto at least one end wall member, arevolvable ball mounted in each opening for horizontal Vmovementtherein, the inner end of each opening being-shaped yto -preventhorizontal movementof the associated 'ball toward said cavity beyond alimiting position wherein the periphery of the ball extends into saidcavity, and spring means in each opening for resiliently lbiasing theassociated ball into said limiting position.

'11. The 'combination as defined in claim 10 wherein eachside wallmember `provides recess means forreceiving the associated end of saidone end wall member.

l-2..'i`he combination as defined in claim l1 wherein References Citedin the le of this patent UNITED STATES PATENTS Ray Sept. 27, 1949 HaasApr. 17, 1956 Pierce et al Apr. 29, 1958 Johnson et a1 Dec. 16, 1958Pierce Jan. 5, 1960

